zoom/pan to route when it doesn't fit on the screen

WebContent/base/osrm/OSRM.MapView.js

@@ -18,6 +18,36 @@ or see http://www.gnu.org/licenses/agpl.txt.
 // map view/model
 // [extending Leaflet L.Map with setView/fitBounds methods that respect UI visibility, better layerControl] 
 OSRM.MapView = L.Map.extend({
+	_boundsInsideView: function(bounds) {
+		var viewBounds = this.getBounds(),
+		viewSw = this.project(viewBounds.getSouthWest()),
+		viewNe = this.project(viewBounds.getNorthEast()),
+		sw = this.project(bounds.getSouthWest()),
+		ne = this.project(bounds.getNorthEast());
+
+		if (viewNe.y > ne.y) { // north
+			return false;
+		}
+		if (viewNe.x < ne.x) { // east
+			return false;
+		}
+		if (viewSw.y < sw.y) { // south
+			return false;
+		}
+		if (viewSw.x > sw.x) { // west
+			return false;
+		}		
+		return true;
+	},
+	setViewBounds: function(bounds) {
+		var zoom = this.getBoundsZoom(bounds);			// maximum zoom level at which the bounds fit onto the map
+		
+		if( this._zoom > zoom ) {						// if current zoom level is too close change zoom level and recenter
+			this.setView(bounds.getCenter(), zoom);
+		} else if(!this._boundsInsideView(bounds)){	// if current zoom level is okay, but bounds are outside the viewport, pan
+			this.setView(bounds.getCenter(),  this._zoom);
+		}
+	},	
 	setViewUI: function(position, zoom, no_animation) {
 		if( OSRM.G.main_handle.boxVisible() ) {
 			var point = this.project( position, zoom);
@@ -26,6 +56,23 @@ OSRM.MapView = L.Map.extend({
 		}
 		this.setView( position, zoom, no_animation);	
 	},
+	setViewBoundsUI: function(bounds) {
+		var southwest = bounds.getSouthWest();
+		var northeast = bounds.getNorthEast();
+		var zoom = this.getBoundsZoom(bounds);
+		var sw_point = this.project( southwest, zoom);
+		if( OSRM.G.main_handle.boxVisible() )
+			sw_point.x-=OSRM.G.main_handle.boxWidth()+20;
+		else
+			sw_point.x-=20;
+		sw_point.y+=20;
+		var ne_point = this.project( northeast, zoom);
+		ne_point.y-=20;
+		ne_point.x+=20;
+		bounds.extend( this.unproject(sw_point,zoom) );
+		bounds.extend( this.unproject(ne_point,zoom) );
+		this.setViewBounds( bounds );	
+	},	
 	fitBoundsUI: function(bounds) {
 		var southwest = bounds.getSouthWest();
 		var northeast = bounds.getNorthEast();

WebContent/routing/OSRM.Routing.js

@@ -71,6 +71,8 @@ showRoute: function(response) {
 		OSRM.Routing._snapRoute();
 	}
 	OSRM.Routing._updateHints(response);
+	var bounds = new L.LatLngBounds( OSRM.G.route._current_route.getPositions() );
+	OSRM.G.map.setViewBoundsUI(bounds);	
 },
 showRoute_Dragging: function(response) {
  	if(!response)